The central nervous system (CNS) is one of the
last systems to mature and is still quite immature at
birth. There are six stages of CNS development.
The first three stages (dorsal induction, ventral
indication, and neurulation) are completed before
the time of viability for preterm infants. The last
three stages (migration, organization, and myelination)
occur, in part, during the period infants are in
intensive care units.